VT-02Secure loose boards and flatten the subfloorWalk the floor and mark any board that moves, squeaks or feels soft, then screw it down into the joist below with countersunk wood screws, driven flush so nothing stands proud. Before you drill or screw into a suspended timber floor, remember pipes and cables can run underneath it — use a detector, but still expect something to be there and prove otherwise, since detectors miss pipes taped to joists or cables in conduit. Find your stopcock first (usually under the kitchen sink) and check it turns, and if you have any doubt at all, isolate the circuit at the consumer unit before you start. Sand down high spots and fill gaps wider than 3mm with a flexible timber floor filler, then vacuum again once it's dry.